We have a utilities plugin we wrote for our printers. It is mostly just a set of simple utilities (e.g. load/unload filament, calibration, etc.) . For some reason when the plugin is enabled the settings dialog has a spinning Save button and you cannot save changes for everything - not just our plugin). if we disable the plugin the problem goes away. I'm sure it is probably something we either don't have in the plugin that we should (e.g. a required call) or some event to which we're not responding correctly.
Any ideas/suggestions on where to start looking?